Cross-Reactivity and Neutralization Capacity of Polyspecific Antivenom Produced by Razi Institute against Three Species of Buthidea Family Scorpions

Abstract :Scorpion sting is a significant health problem in southern provinces of Iran. Many thousands of people are stung by different species of scorpions annually. More than 60 scorpion species have been reported to be present in Iran. However razi Institute manufactures polyvalent antivenom against only six species of scorpions, excluding Buthacus macrocentrus , Apistobuthus susanae and Vachoniolus iranus, wide spread scorpion species in south region of Iran. In this research, after collecting scorpions (at night),milking by elctroshock method, the venom of its lyophilized and the LD50 was determined. The fractions were then separated by gel chromatography and HPLC. Using SDS page electrophoresis, the fractional molecular weight was determined. At the end, potency test of these scorpion venoms was carried out in the vicinity of the antiserum produced by the Razi Institute on the animal.In the present work we tried to investigate the cross reactivity of present antivenom against these excluded scorpion species. The antisera production of the Razi Institute was able to neutralize the 33 LD50 of Apistobuthus susanae venom. This antivenom could neutralize Buthacus macrocentrus as well as Vachoniolus iranus scorpion venoms by 41 LD50 and 15 LD50 respectively . According to the World Health Organization (WHO) , antiserums should be made locally and against animal species.Therefore based on the results obtained in the present study it can be concluded that although the venom of these scorpion species are not included in the antivenom production but the present polyvalent antivenom is able to be used in patients stung by these 3 species of scopions too. The powerity of anti-serum neutralizing against the venom of other species of scorpions is based on the constructional similarity and cross-reactivity of different species of venom scorpions